/Engine/Source/Runtime/Core/Public/Experimental/Async/AwaitableTask.h
Busy wait until the Task is launched from another Thread, this can be useful if we want to build chained tasks. So that we can wait until the first task launched it, otherwise if we would Await the task directly it might be executed immediately and before the first task completes.
void BusyWaitUntilLaunched() const